1. Field of the Invention
The present invention relates to a discharge-controlled method for a compressed air-controlled wet settling machine for the preparation of mineral mixtures, particularly for the washing of raw coal, in which the preparation takes place through pulsation of a separating liquid in a work chamber, whereby the pulsation is controlled by means of inlet and outlet valves and results in a layering of the minerals on the settling material carrier, and more particular to such a method in which the level of the layer of the specific heavy materials in each case is measured by at least one member through which an actual-reference regulation controls a discharge apparatus of the heavier minerals.
2. Description of the Prior Art
From the German Pat. No. 932,481, a method and an apparatus for the regulation of the discharge from wet settling machines are known, in which, through a measuring circuit, and during the time interval in which the heavy mineral layer is in its lower position of rest, the level of the layer is scanned. The switching into circuit of the measuring circuit takes place during a predetermined angle .alpha. of the cycle of the rotary-slide inlet and outlet valves in the corresponding operating phase of the settling procedure symmetrically with respect to the movement of the inlet and outlet valves, during the time in which the inlet and outlet valves are closed.